1. Field of the Invention
The present invention relates to a method and an apparatus for controlling uplink transmission power of a mobile terminal in a long term evolution (LTE)-based small cell base station system.
2. Description of Related Art
An uplink power control in a wireless communication system is a technology of optimally controlling transmission power of a mobile terminal. The uplink power control is to keep a predetermined level of received channel quality (for example, received signal-to-interference plus noise ratio (SINR), received signal to noise ratio (SNR), or the like) that a base station requires, minimize interference with neighbor base stations, and maximize battery life of the mobile terminal. The uplink power control is a main element for radio resource management (RRM).
The power control needs to be optimized in consideration of a radio channel state including a path loss, shadowing, or the like while minimizing interference with neighbor cells.
For this purpose, an open-loop power control and a closed-loop power control for a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH) are defined in the LTE.
Meanwhile, if the transmission power exceeds maximum power that the mobile terminal may transmit, PUSCH receive performance of the base station is degraded, uplink performance is degraded, and battery consumption of the mobile terminal becomes severe. Therefore, a method for reducing battery to consumption of a mobile terminal by preventing transmission power from exceeding maximum power that the mobile terminal may transmit is required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.